Law enforcement agencies from 20 countries working together shut down a major computer hacking forum, and U.S. officials filed criminal charges against a dozen people associated with the website, the U.S. Department of Justice announced.

Darkode.com on Wednesday displayed a message saying the site and domain had been seized by the FBI and other law enforcement agencies.

Darkode, a password-protected online forum for criminal hackers, represented one of the gravest threats to the integrity of data on computers across the world, according to David Hickton, U.S. attorney for the Western District of Pennsylvania. "Through this operation, we have dismantled a cyber hornets' nest of criminal hackers which was believed by many, including the hackers themselves, to be impenetrable."

Five of the defendants face charges in Hickton's district.

Darkode allowed hackers and other cybercriminals to sell, trade and share information and tools related to illegal computer hacking, the law enforcement agencies alleged.

Before becoming a member of Darkode, prospective participants were allegedly vetted through a process that included an invitation by a member, the DOJ said in a press release. The prospective member then pitched the skill or products he or she could bring to the forum.

Darkode members allegedly used each other's skills and products to infect computers and electronic devices of victims around the world with malware, the DOJ said.

The takedown of the forum and the charges announced Wednesday came after the FBI's infiltration of Darkode's membership.

The charges are part of a coordinated effort of law enforcement authorities from 20 nations to charge, arrest or search 70 Darkode members and associates around the world. The nations involved included Australia, Canada, Colombia, Germany, Israel, Nigeria and the U.K.

The dozen now charged with hacking in connection with Darkode include two who have already pleaded guilty. Aleksandr Andreevich Panin, aka Gribodemon, 26, of Tver, Russia, pleaded guilty on Jan. 28, 2014, while Hamza Bendelladj, aka Bx1, 27, of Tizi Ouzou, Algeria, pleaded on June 26. Both made the pleas in U.S. District Court for the Northern District of Georgia in connection with developing, distributing and controlling SpyEye, a malicious banking Trojan.

Bendelladj and Panin advertised SpyEye to other members on Darkode. One of the servers used by Bendelladj to control SpyEye contained evidence of malware that was designed to steal information from approximately 253 financial institutions around the world. Panin and Bendelladj will be sentenced at a later date.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's email address is grant_gross@idg.com.